// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "media/filters/h264_bit_reader.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace media {

TEST(H264BitReaderTest, ReadStreamWithoutEscapeAndTrailingZeroBytes)
{
    H264BitReader reader;
    const unsigned char rbsp[] = { 0x01, 0x23, 0x45, 0x67, 0x89, 0xa0 };
    int dummy = 0;

    EXPECT_TRUE(reader.Initialize(rbsp, sizeof(rbsp)));

    EXPECT_TRUE(reader.ReadBits(1, &dummy));
    EXPECT_EQ(dummy, 0x00);
    EXPECT_EQ(reader.NumBitsLeft(), 47);
    EXPECT_TRUE(reader.HasMoreRBSPData());

    EXPECT_TRUE(reader.ReadBits(8, &dummy));
    EXPECT_EQ(dummy, 0x02);
    EXPECT_EQ(reader.NumBitsLeft(), 39);
    EXPECT_TRUE(reader.HasMoreRBSPData());

    EXPECT_TRUE(reader.ReadBits(31, &dummy));
    EXPECT_EQ(dummy, 0x23456789);
    EXPECT_EQ(reader.NumBitsLeft(), 8);
    EXPECT_TRUE(reader.HasMoreRBSPData());

    EXPECT_TRUE(reader.ReadBits(1, &dummy));
    EXPECT_EQ(dummy, 1);
    EXPECT_EQ(reader.NumBitsLeft(), 7);
    EXPECT_TRUE(reader.HasMoreRBSPData());

    EXPECT_TRUE(reader.ReadBits(1, &dummy));
    EXPECT_EQ(dummy, 0);
    EXPECT_EQ(reader.NumBitsLeft(), 6);
    EXPECT_FALSE(reader.HasMoreRBSPData());
}

TEST(H264BitReaderTest, SingleByteStream)
{
    H264BitReader reader;
    const unsigned char rbsp[] = { 0x18 };
    int dummy = 0;

    EXPECT_TRUE(reader.Initialize(rbsp, sizeof(rbsp)));
    EXPECT_EQ(reader.NumBitsLeft(), 8);
    EXPECT_TRUE(reader.HasMoreRBSPData());

    EXPECT_TRUE(reader.ReadBits(4, &dummy));
    EXPECT_EQ(dummy, 0x01);
    EXPECT_EQ(reader.NumBitsLeft(), 4);
    EXPECT_FALSE(reader.HasMoreRBSPData());
}

TEST(H264BitReaderTest, StopBitOccupyFullByte)
{
    H264BitReader reader;
    const unsigned char rbsp[] = { 0xab, 0x80 };
    int dummy = 0;

    EXPECT_TRUE(reader.Initialize(rbsp, sizeof(rbsp)));
    EXPECT_EQ(reader.NumBitsLeft(), 16);
    EXPECT_TRUE(reader.HasMoreRBSPData());

    EXPECT_TRUE(reader.ReadBits(8, &dummy));
    EXPECT_EQ(dummy, 0xab);
    EXPECT_EQ(reader.NumBitsLeft(), 8);
    EXPECT_FALSE(reader.HasMoreRBSPData());
}

} // namespace media
